Differential fertility restoration of restorer genes to WA-cytoplasmic male sterility system in rice (Oryza sativa L.).

摘要

An experiment was conducted in New Delhi, India, to study the inheritance of fertility restoration in rice. The F1 plants from the cross between PRR72 and P1292 were testcrosses to the cms line PMS2A to develop a 3-way testcross progeny (TWCF1) for allelic relationship studies. Pollen and spikelet fertility of the plants were assessed in each case and plants were classified as fully fertile (FF), semi-fertile (SF), semi-sterile (SS) or completely sterile (CS). Analysis of pollen and spikelet fertility in F2 population of the cross between PMS2A and PRR72 revealed a digenic mode of inheritance of fertility restoration. The frequency of FF, SF plus SS and CS plants fitted well to 9:6:1 F2 segregation ratio displaying an epistasis with incomplete dominance. The segregation pattern for pollen and spikelet fertility in F2 population of the cross involving PMS2A and P1292 corresponded to a trigenic segregation ratio of 27:30:7 for FF, SF plus SS and CS plants indicating that the presence of 3 dominant genes imparted normal fertility in the segregating plants. The appearance of SS plants in addition to FF and SF plants suggests that PR72 and P1292 possessed non-allelic strong and allelic weak restorer genes..